Automatic load-brake.



No. 836,912. PATENTBD NOV. 27, 1906.

' A, BECK.

AUTOMATIC LOAD BRAKE. APPLICATION runn 8E1T.7,1906.

. M PA PETER: cm, wassmarau, u. c.

UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Nov. 27, 1906.

Application filed September 7,1906. Serial No. 333,627-

To wZZ whom it may concern.-

Be it known that I, MATTHIAS A. Back, a citizen of the United States,residing at Milwaukee, in the county of Milwaukee and State ofWisconsin, have invented certain new and useful Improvements inAutomatic Load-Brakes, of which the following is a specification,reference being hadto the accompanying drawings, forming apart thereof.

This invention relates more particularly to brakes for hoists andsimilar machines of the class of that shown and described in UnitedStates Letters Patent No. 697,393, dated April 8, 1902.

The main objects of the present invention are to automatically controlwith certainty and precision the descent of the loadby the operation ofthe motor, to avoid collar or radial surface friction during theoperation of lowering a load, to equally distribute the pressure on thefriction-surfaces, to secure uniformity of rubbing velocity for theentire active surface of the brake, and generally to improve theconstruction and operation of brakes of this class.

The invention consists in certain novel features of construction and inthe peculiar arrangement and combinations of parts, as hereinafterparticularly described, and pointed out in the claims.

In the accompanying drawings like characters designate the same parts inboth figures.

Figure l is a vertical axial section of the brake on the line 1 1, Fig.2, as applied to a hoist; and Fig. 2 is a vertical cross-section on thebroken line 2 2, Fig. 1.

The brake-shaft a, passing continuously through the brake, is supportedat each end thereof in bearings b. On this shaft is loosely mounted acylindrical friction-shell 0. Within this shell two beveled expandingheads d and e are mounted on the shaft a and have a feather or otherdriving connection therewith, the head e being movable axially towardand from the head d. The head 6 has a cylindrical hub or extension f, on

which are mounted one or more externallybeveled and axially movableexpanding rings 9, which are made to turn therewith by a key h or othersuitable means.

Between the opposing beveled faces of the heads cl and e and of theseveral expanding rings 9 are interposed internally-beveled expansiblefriction-rings 'i, the outer cylindrical faces of which are fitted inthe shell 0. These rings are completely severed on one side and arepreferably partially severed at intervals, as shown in Fig. 2, to enablethem to con form more readily to the shell 0 when they are expandedtherein. At the end of the brake next to the head e a sleeve j isthreaded thereon. The adjacent end of the shell 0 is provided with adetachable head it, which has a hub fitted to turn on said sleeve. Atthe opposite end of the brake a ratchet-wheel Z is attached to theshell, and pawls m, pivoted to an adjacent part of the frame, hold saidshell against turning in one direction, while they permit it to turnfreely in the other direction. A motor or driving-shaft n is connectedwith the brake-shaft a by a pinion 0 and gear p. In the present case ahoisting-drum g is connected by a gear 7* with a pinions on the sleeveBetweenthe beveled expanding head cl and the adjacent head of the shell0 the brake-shaft a is formed-or provided with a collar 25, and betweenthe outer end of the sleeve 9' and the adjacent bearing p said shaft isformed or provided with a colar to.

In connection with a hoist the improved brake herein shown and describedoperates as follows: In hoisting a load the motor or driving-shaft n,being turned in the direction indicated by the arrow 33, turns thebrakeshaft a and the hoisting-drum g in directions indicated bycorrespondingly-designated arrows. When the shaft a is turned in thedirection indicated by the arrow as thereon, it operates, primarily, toscrew the sleeve 7' against the head e, thereby forcing it toward thehead (1 and by the interengagement ,of the beveled faces of said headsand of the rings g and i expanding the rings 0; against the inclosingshell 0. The rings '5 being thus expanded and held in fast frictionalengagement with the shell 0, the several parts of the brake, includingthe shell ,0 and sleeve 1', are turned with the shaft a. In lowering theload, which tends to turn the hoisting-drum g and the parts of the brakein the directions indicated by the arrows y, the shell 0 is preventedfrom turning by engagement of the pawls m with the ratchet-wheel Z. Themotor or driving-shaft n being turned in the direction indicated by thearrow y thereon tends to screw the sleeve on the shaft a away from thehead 6, and thereby to release or reduce the frictional engagementbetween the rings 71 and the shell 0, permitting said rings to slip inthe stationary shell and the IIO load to descend at a rate correspondingwith the speed of the motor or driving-shaft 1. If the motor ordriving-shaft is stopped, the descent of the load will be instantlyarrested by its action upon the screw-threaded sleeve j, tending toexpand the rings 7', in the shell 0. The heavier the load the greaterwill be the force tending to expand the friction-rings i and thestronger will be the hold of the brake.

It will be observed that the movement of the load both in lifting orlowering it is positively governed by the operation of the motor ordriving shaft, backward rotation of said shaft being necessary torelease or reduce the hold of the brake and permit the load to descend.It will also be observed that in the operation of the brake there islittle or no end thrust of the brake-shaft a in its bearings, andconsequently no radial surface or collar friction, that the pressureagainst the opposing friction-surfaces of the brake is equallydistributed, and that a uniform rubbing velocity is secured, the entireactive surface of the brake being of the same or uniform radius.

For some purposes it is desirable to reverse the connections of themotor and the loadviz., to gear the motor with the sleeve 7' and theload with the shaft a, the construction and operation of the brakeremaining essentially the same as hereinbefore described.

I claim 1. In an automatic load-brake the combi nation of a shaft havingtwo expanding heads mounted thereon, one of said heads being movableaxially toward and from the other, an expansible friction-ring betweensaid heads, a shell surrounding said ring and free to turn in onedirection, and means for holding said shell against turning in theopposite direction, substantially as described.

2. In an automatic load-brake the combination of a shaft havingbeveledheads mounted thereon, one headbeing movable axially toward and from theother, an expansible beveled friction-ring interposed between saidheads, a shell surrounding said ring and free to turn in one direction,and means for holding said shell against turning in the oppositedirection, substantially as described.

3. In an automatic load-brake the combination of a shaft, opposingbeveled heads mounted thereon and having rotating connection therewith,one head being movable v axially with relation to the other, a number ofinternally-beveled and expansible frictionrings confined between saidheads, an externally-beveled expanding ring interposed between thefriction-rings, a friction-shell surloo rounding said rings and free torotate therewith in one direction, and means for preventing said shellfrom turning in the other direcx tion, substantially as described.

4. In an automatic load-brake the combination of a shaft, beveled headsmounted thereon and having rotating connection therewith, one head beingmovable axially with relation to the other, a number ofinternallybeveled expansible friction-rings and one or moreexternally-beveled expanding rings confined side by side between saidheads and upon the extended hub of one head, a friction-shellsurrounding said rings, and free to turn therewith in one direction, andmeans for preventing said shell from turning in the other direction,substantially as described.

5. In an automatic load-brake the combination of a shaft, beveled headsmounted thereon and having rotating connection therewith, one head beingmovable axially with relation to the other, one or more beveledexpansible friction-rings interposed between said heads, afriction-shell surrounding said ring and free to turn therewith in onedirection, means for preventing said shell from turning in the otherdirection and a sleeve threaded upon said shaft adjacent to the movablehead, substantially as described.

6. In an automatic load-brake the combination of a shaft, opposingbeveled heads mounted upon and having rotating connection with saidshaft, one head being axially movable relatively to the other, a beveledexpansible friction-ring interposed between said heads, a friction-shellsurrounding said ring and free to turn therewith in one direction, meansfor reventing said shell from turning in the ot er direction and asleeve threaded on said shaft adjacent to the movable head, said sleeveand the other head being confined between collars or shoulders on saidshaft, substantially as described.

In witness whereof I hereto affix my signature in presence of twowitnesses.

MATTHIAS A. BECK.

